Peel, dice and wash the potatoes. Cook the potato cubes in boiling water under tender; drain. In a large bowl, mash the potatoes. Add the remaining ingredients and blend well.
Spray a 3-quart casserole or 9" x 13" baking dish with nonstick spray. Pour the potatoes into the casserole dish and bake at 350 F for 20 to 25 minutes or until top starts to brown slightly.